When calculating the recurrence risk for a complex, possibly polygenic disorder with a couple who already have one child with the disorder, which additional factorhasthe greatest impact on increasing this risk?
A)The child with the disorder is male, and the overall incidence of the disorder is twice as high in males than females.
B)Both the mother and the father are heavily exposed to a variety of chemicals in their workplaces.
C)The father has a nephew with a mild form of the same disorder.
D)The mother has a brother who also has the same disorder.

Question

Quizplus · Accepted Answer

Having a close relative (in this case a first-degree relative) who also expresses the disorder increases the likelihood that the disorder is more the result of genetic influences than environmental influences and that more risk alleles are present.

When Calculating the Recurrence Risk for a Complex, Possibly Polygenic